We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_".  But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
do so.

Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something.  So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:

1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
   CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
   for pasting.

(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).

Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
4) Make everyone use them.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Tested-by: James Hogan <james.hogan@imgtec.com> (metag)

The shell '.' command is not required to search the current directory as
a fallback and in fact newer versions of bash in sh-mode do not do this.
Force reading the file from the current directory if $KCONFIG_CONFIG
contains no '/'.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Its possible to superseed the config file with KCONFIG_CONFIG and have
completely no .config in the tree. The current script is sourcing
.config in every case, so the kernel will never build succesfully. This
patch fixes that issue by sourcing KCONFIG_CONFIG instead.
Signed-off-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Commit 1f2bfbd0 ("kbuild: link of
vmlinux moved to a script") introduced in v3.5-rc1 broke kallsyms on
architectures which have symbol prefixes.

The --symbol-prefix argument used to be added to the KALLSYMS command
line from the architecture Makefile, however this isn't picked up by the
new scripts/link-vmlinux.sh. This resulted in symbols like
kallsyms_addresses being added which weren't correctly overriding the
weak symbols such as _kallsyms_addresses. These could then trigger
BUG_ONs in kallsyms code.

This is fixed by removing the KALLSYMS addition from the architecture
Makefile, and using CONFIG_SYMBOL_PREFIX in the link-vmlinux.sh script
to determine whether to add the --symbol-prefix argument.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NBob Liu <lliubbo@gmail.com>

Reported-by: NJan Engelhardt <jengelh@inai.de>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

... at least in the top-level Makefile and scripts/link-vmlinux.sh.
There are some more instances of the 'echo <error>; exit 1' pattern in
some arch Makefiles and kconfig.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

ia64 build failed like this:

  CC      init/version.o
  LD      init/built-in.o
  KSYM    .tmp_kallsyms1.o
ld: .tmp_kallsyms1.o: linking constant-gp files with non-constant-gp files
ld: failed to merge target specific data of file .tmp_kallsyms1.o
make: *** [vmlinux] Error 1

This was introduced when link of vmlinux was migrated to a script.
Add missing option to as to fix this.
Reported-by: NTony Luck <tony.luck@gmail.com>
Tested-by: NTony Luck <tony.luck@gmail.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Move the final link of vmlinux to a script to improve
readability and maintainability of the code.

The Makefile fragments used to link vmlinux has over the
years seen far too many changes and the logic had become
hard to follow.

As the process by nature is serialized there was
nothing gained including this in the Makefile.

"um" has special link requirments - and the
only way to handle this was to hard-code the linking
of "um" in the script.
This was better than trying to modularize it only for the
benefit of "um" anyway.

The shell script has been improved after input from:
Arnaud Lacombe <lacombar@gmail.com>
Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Arnaud Lacombe <lacombar@gmail.com>
Cc: Nick Bowler <nbowler@elliptictech.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: NMichal Marek <mmarek@suse.cz>